Counterbalanced crank-shaft.



W. S. HARLEY.

COUNTERBALANCED CRANK SHAFT.

APPLICATION FILED SEPT.22.' I911- ]Patented Apr. 23, 1918.

S'SHEETS-SHEET 1- mnuum i W. S. HARLEY.

COUNTERBALANCED CRANK SHAFT.

APPLICATION FILED szvpzz. m1.

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3 SHEETS-SHEET 3.

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ii i LIAM S. HLEY, 0F MILWAUKEE, WISCONSIN, ASSIGNOR T0 HARLEY-DAVIDSONMOTOR 00., OF MILWAUKEE, WISCONSIN.

matador.

Specification of Letters Patent.

Patented Apr. 23, 1191.

Application filed September 22, 1917. Serial No. 192,658.

To all whom it may concern: I Be it known that 1, WILLIAM S. HARLEY, acitizen of t he llnited States, and resi dent of Milwaukee, in thecounty of Milwaukee and State of Wisconsin, have invented certain newand useful Im rovements in Counterbalanced Crank-S afts; and I do herebydeclare that the following is a full, clear, and exact descriptionthereof. y invention relates broadly to internal combustion engineconstruction, and more specifically to crank shafts for such engines.Through considerable experiment it has been found that internalcombustion engines provided with counter-balanced crank shafts operatewith greater ease and smoothness than those engines not so equipped.

It is, therefore, one object of this inven tion to provide an internalcombustion engine, particularly motor-cycle engine. with a crank shafthaving counter-balance.

weights for preventing the stopping of the movement of the parts whenthe same are on dead center. p

In carrying out the foregoing object, it also has been discovered thatit is essential that the counterbalanced weights be readily detachablefrom the crank shaft to permit one piece annular ball or roller bearingraces to be slipped into osition. It is well-known that split races orholding ball or roller bearings are not practicable and therefore thepresent invention has been designed with the idea of permitting theready assemblage of one piece bearing races, as well as one piececonnecting rods, with a one piece crank shaft.

An additional object is to provide a one piece crank shaft, adapted tobe operated by a pair of pistons, which are connected by a flatplate,.against the opposite sides of which the connecting rods from saidpistons are adapted to enga e.

With the above and ot or objects in View,

the invention resides in the novel features of construction, combinationand -arrange ment of parts, which will be hereinafter more particularlydescribed and claimed, and shown in the drawings, wherein:

Figure 1 represents a plan view of a crank shaft constructed inaccordance with my invention, the same having portions ofconnecting'rods mounted thereon, said connecting rods being shown insection.

strength of parts Fig. 2 is an end view of the crank shaft.

Fig. 3 is a fragmentary sectional view showing more particularly themanner of detachably connecting the counter-weights to the shaft.

Fig. 4 is a detail transverse section taken substantially on the planeof the line H ofFig. 3. i

Fig. 5 is a view similar to Fig. 1 showing more particularly thepreferred manner of holding'the connecting rod bearings in position, and

.Figs. 6 and 7 are detail transverse sections taken on the plane of theline 67 of Fig. 5'and showing two positions of the connecting rodbearing washer.

The crank shaft, which forms the basis of the present invention isprimarily ada ted for use in motorcycle power plants, in w 'ch theoperating cylinders are directly opposed. It has long since been foundthat the only practical manner of constructin an internal combustionengine crank sha t is to cast the same of suitable etal in one piece. Ifthis is not done, the required rigidity and is not obtained and theresult will be uniformly unsatisfactory.

Therefore, the crank shaft, shown in the accompanying drawings, is castin one piece, and comprises apair of rightangular cranks 1, and sincethis shaft is to be used with a two cylinder engine, a pair of s indles2 and 2 projecting in opposite directlons and extended from the corresonding arms 1 of the cranks, and a flat, e ongated connecting plate 3,which unites the other arms 1 of the cranks, the latter being formedintegrall with the opposite flat faces of the late an adjacent theopposite ends thereof. he plate 3 is relatively thin crank shaft to beconstructed as light as possible, but is of a width substantially twicethe diameter of the crank arms to procure the necessary strength. Thespindles 2 and 2 are adapted to be journally disposed in the oppositewalls 4 of a crank casing, such as shown in Fig. 1 of m co-pendingapplication, Serial No. 19211 one of said spindles being adapted to havea gear keyed thereto, while the other end carries a flywheel. The freeends of the spindles are reduced and threaded as at 5 to receive nuts orthe like for holding the parts thereon.

Each of the arms 1 of the cranks 1 is to permit the provided with ahorizontally extending bore it will be noted that the bores 6 extend atrightangles to the axis of rotation of the spindles, and, also, that thecounter-weights 8 are adjacent the free ends of said arms 1. The otherportion of" the arms, that is adjacent' the angle of the cranks, isprovided with bosses 9 against the flat end of which the retaining nuts10 engage, said nuts being screwed on the threaded ends of the stems 7.By such an arrangement the mere removal of the nuts 10 will permit thedetachment of the counter-weights 8.

As hereinbeforeindicated, the counterweights are adapted to be removedwhenever it is necessary to detach the connecting rods 11 or any of theparts associated therewith, it being obvious that said parts areassembled before the weights are initially attached to the,cranks. Theends of the connecting rods, which are for engagement with the cranks,are in the form of one piece annular members 12, the openings of whichare somewhat-greater in diameter than the ogrerating surfaces 13 of saidcranks.

Roller bearings 14 are preferably used for overcoming friction betweenthe connecting rods and the crank and these are held in operativeposition between one piece annular bearing races or rings 15. The usualspacing rings 16 are also provided, which are adapted to space therollers predetermined distances apart.

These one-piece ring-like members are assembled by slidin the same overthe ends of the spindles an then around the cranks 1 until they are inoperative position on the bearing. surfaces 13, and when thusly disposedthey will, also, engage the opposite faces of the connecting plate 3.This plate holds the members against movement in one direction, andretainin washers 17* or 17 which are, also, assemb ed by disposing thesame over the spindles, prevent movement of the parts in the oppositedirection. The washers 17, which are shown in Fig. 1, are held inoperative position by means of pins 18 which extend transversely throughthe arms 1 of the cranks. In Figs. 5, 6, and 7, however, is shown adifierent and preferred means for positively holding these retainingwashers, numbered 17 in these figures, in position. In this form theopening in the washer 17' is substantially hexagonal, the alternatesides of the opening, however, being curved outwardly substantiallyconcentrio with the riphery of the washer, as shown at 19. he washersare provided with openings of this shape to permit them to be disposedover collars 20 of similar shape which are formed integrally with thearms 21 of the arms 1" between these collars and said surfaces 13 areround whereby, after the washers are slipped over the polygonal collars20, they may be rotated to aline the semi-circular pin receiving notches22 and 23 formed respectively in one wall of the opening of the washersand the collars 20.

Fig. 6 shows one washer being slipped over a collar 20, while Fig. 7illustrates a washer and collar after the pin receiving notches havebeen alined and provided with a retaining pin 2i. The pin obviouslyprevents rotation of the washer and the collar prevents outward movementthereof. Each pin 24 is retained in operative position by the engagementof one arm of a rightangular bracket therewith, the other arm of whichis apertured and dis osed over the stem of the adjacent counteralancemember and is held by the nut 10.

From the foregoing description taken in connection with the accompanyingdrawings, it will be obvious that a very simple arrangement has beendevised, whereby one piece bearing races, or rings, and other oneiecemembers which are adapted to be used in connection therewith, may bequickly and easily assembled in position on a one-piece crank shafthavin detachable counterweights. Various c anges in the size andproportion may be made without departing from any of the principles ofthe invention, as set forth in the appended claims, for instance, acrank shaft of similar construction can be used with equal success withengines having more than two cylinders.

I claim 1. A crank shaft of the class described comprising a pair ofopposed cranks, one arm of each crank having a bore extendinglongitudinally therethrough, a pair of spindles pro ecting in oppositedirections from the outer portion of the cranks, a counter-balanceweight for each crank, a stem extending from each counter-balanceweight, said stems being disposed in opposite directions through thebores, and

said bores.

2. A crank shaft of the class described comprising a crank, one armthereof havin a bore extending therethrough, a pair 0 spindles extendingin opposite directions from the arms of the crank, a counter-balanceweight, a stem extending from the weight and adapted to be disposed inthe bore of the crank, and means on the stem for detachably securing thestem in the bore.

Zf A device of the class described comprising in combination, a crankshaft, 9. connecting rod disposed thereon, a poly sided collar formed onsaid crank shaft, a washer having a polygonal opening similar to saidcollar, said washer being adapted to slide over said collar when thesides of the latter coincide with the walls of the V opening, whereby toengage the connecting rod, and means to prevent rotation of said washer.

\ 4. A device of. the class described comprising in combination, a crankshaft, a

connecting rod disposed thereon, a polysided collar formed on said crankshaft and spaced from the connecting rod, a washer having a polygonalopening similar to said sided collar formed on said crankshaft andspaced from the connect rod, said collar having a notch formed t erein,a washer having a polygonal opening sinular to said collar, the formerhaving a notch in one wall to aline with the first mentioned notch,

said washer being adapted to slide over said collar to be positionedbetween the same and the connecting red when the sides of said collarand the walls of the opening coincide, and a pin disposed in saidnotches when aligned, whereby to prevent rotation of said washer.

6. A device of the class described comprising in combination, a crankshaft, a connecting rod d sposed thereon,.. a collar formed on saidcrank'shand spaced w v dim t from the connecting rod, a washer movableover said collar w en in one osition and disposed between the same anconnecting rod, said collar and washer having notches adapted to alinewhen the washer is in one position, a pin disposed in. said alinednotches, and a rightangular bracket secured by one arm to said crankshaft, the other arm being engaged with said pin to retain the same inoperative osition.

7, A device of the class mescribedcomprisin in combination, acrankshaft, one arm 0 the crank havinga bore extending therethrough, aconnecting rod disposed on said crank shaft, a collar formed on saidcrank shaft, a washer for holding the connectin' rod on the shaft, saidwasher being movab e over said collar when in one position, said collarand washer having notches adapted to aline when the washer is in oneposition a pin disposed in said notches when alined, a counter-balancingmember,

a stem extending from said member and disposed through the bore in thecrank arm,

one end of said stem extending beyond said crank arm, a rightangularbracket havin one arm disposed over said projected end 0 the sten'1,'theother arm being engaged with said pin and a fastening mern er on theprojected racket thereon.

In testimony that I claim the foregoing l[ have hereunto set my hand atMilwaukee, in the county of Milwaukee and State of Wisconsin.

end of the stem to retain the

